Catalytic Production of 1‐Octadecanol from Octadecanoic Acid by Hydrotreating in a Plug Flow Reactor

Abstract

1-Octadecanol (stearic alcohol) has uses ranging from lubricants to perfumes. The production of 1-octadecanol from octadecanoic acid (stearic acid) was investigated in a liquid-phase trickle-bed reactor by hydrogenating octadecanoic acid using a Ni/Co/Mo sulfide catalyst. The primary reactions occurring in the reactor were the desired conversion of octadecanoic acid to 1-octadecanol and the subsequent undesired conversion of 1-octadecanol to octadecane. A model was developed to predict these two reactions. The model found to be most useful for this system was a series-parallel reaction first order in octadecanoic acid and 1-octadecanol and pseudozero order in hydrogen for both reactions. The activation energies of the first and second reactions were 63.7.8 and 45.6 kJ/mol, respectively. From these values, the conversion of octadecanoic acid and the selectivity to the desired product as functions of temperature, space velocity, and inlet octadecanoic acid concentration were estimated. The model predicts the maximum productivity of 1-octadecanol occurs at higher temperatures with short residence times. Parametric plots show productivity to be C0.48 g 1-octadecanol/g octadecanoic acid at 566°F and a 0.1 h residence time.